The present invention relates to an oxygen dispenser and more particularly although not necessarily exclusively to oxygen vending systems.
The benefits of inhaling substantially pure oxygen to compensate for hypoxia are becoming increasingly broadly appreciated. Most commonly, individuals suffer from hypoxia following high levels of exertion in a relatively poorly ventilated environment. Such might be the case in a bar or night club particularly but may arise in a health club or other environment. Indeed, in cities where there is a very high level of atmospheric polution from, for example, car exhausts access to substantially pure oxygen or oxygen-enriched air may be an important factor in maintenance of good health.
Existing sources of substantially pure oxygen supply are conventionally simple oxygen cylinder based systems which have a manual valve for dispensing of the oxygen by an attendant or are adapted for self-service and have temporary storage of oxygen in a container intermediate the cylinder and mouth piece. These systems are, however, impractical for widespread usage and it is, of course, impractical to dispense individual oxygen cylinders to users.
It is a general objective of the present invention to provide an oxygen dispensing system that is versatile, being suitable for installation in any of a wide range of different environments and usable in an efficient and economic manner.
According to a first aspect of the present invention there is provided an oxygen dispenser for dispensing substantially pure oxygen or highly oxygen enriched air, which dispenser comprises a housing accommodating an oxygen concentrator in fluid communication with an air inlet of the housing and a dispenser outlet of the housing via pipework, a flow control valve to control flow of oxygen or oxygen-enriched air to the dispenser outlet, the flow control valve being under the control of a controller, the dispenser unit further having a card reader for a mag-stripe, swipe card, smart card or similar or a receiver for credit tokens or other credit data input means whereby credit units may be input to the dispenser controller to dispense oxygen or oxygen enriched air.
The valve is preferably a solenoid-operated valve and it may suitably be operated by the controller to dispense a predetermined volume of oxygen or oxygen enriched air for each unit of credit input by card or token or other means, which may include currency coins or notes.
The card is preferably a coded magnetic stripe (mag-stripe) card which may have the one or more credits on the card deleted following use.
In addition to having the automated control of the valve to dispense oxygen or oxygen enriched air in response to the credit data input by the card, tokens or other means, the unit preferably also has means operable by the user to alter flow rate and/or to switch off flow of oxygen or oxygen-enriched air. The dispenser unit suitably has a dispenser outlet to which a nasal or other dispensing cannula or dispensing mask may be fitted for each dispensing operation and which may be automatically cut off from further oxygen or oxygen-enriched air dispensing supply when the mask or cannula is detached from the dispenser outlet.
In contrast to incorporating one or more oxygen cylinders, the dispenser incorporates an oxygen concentrator, providing a substantially inexhaustible supply of oxygen-enriched air. An oxygen concentrator in its broadest sense is any device that concentrates the oxygen already present in air.
Most oxygen concentrations use PSA (Pressure Swing Adsorption) technology to concentrate the oxygen. PSA consists of a process where a gas is fed at an elevated pressure to a vessel containing an adsorbent matrix. The adsorbent matrix selectively adsorbs one or more of the non oxygen gas components such as Nitrogen and carbon dioxide. Thus, the product gas is enriched in the oxygen and any other components that have had least adsorption. The adsorbent bed is regenerated by: 1. reducing the pressure in the vessel and 2. flowing some high purity gas through the adsorbent particles. At least two adsorbent beds are used so that continuous flow of the enriched gas can be obtained. When one vessel is adsorbing gas, the adsorbent in the other vessel is being regenerated. Typical adsorbent materials which are used comprise carbon molecular sieves, zeolite molecular sleeves, activated carbon, silica gel, and activated alumina.
The oxygen dispenser is particularly efficient when the concentrator is operated continuously. This may have benefits in terms of the useable life of the oxygen concentrator or its maintenance intervals and is particularly useful in avoiding delay in supply of highly oxygen enriched air to the user. Accordingly, the dispenser is particularly preferably adapted to have the concentrator running continuously and configured to disperse the oxygen or oxygen-enriched air into the surrounding atmosphere when the flow control valve is not at its setting to direct flow of the oxygen or oxygen-enriched air to the dispenser outlet.
Suitably the solenoid valve is adapted to selectively alternate between supply to the dispenser outlet or to a venting outlet at a remote location of the dispenser housing away from the dispenser outlet.
The dispenser preferably has an exterior fan to expell air from the dispenser housing.
Preferably the venting outlet has an extractor fan to expell and disperse the oxygen or oxygen-enriched air rapidly.
Alternatively or preferably additionally, the dispenser is suitably adapted so that the oxygen or oxygen-enriched air is re-combined with the oxygen-depleted air from the oxygen concentrator as it is expelled from, or preferably prior to being expelled from, the dispenser housing. Such measures prevent any risk whatsoever of accumulation of oxygen within or in the vicinity of the dispenser other than the harmless small volumes held in the concentrator and associated pipework. There is, therefore no fire hazard and, indeed, the system is far safer than the existing systems that rely on use of pressurised oxygen cylinders.
By way of further improvement, the dispenser housing suitably has an air filtration element covering the air inlet to the housing and which is externally accessible to enable easy replacement. This will facilitate maintenance of the apparatus, reducing the need for internal servicing and is particularly valuable for environments with high levels of atmospheric polution.
For user comfort and to extend the benefits of use of the apparatus it is preferably adapted to introduce fragrance into the oxygen or oxygen-enriched air that it dispenses. Aromatherapy oils of other sources of fragrance may conveniently be introduced by coupling a vessel, such as, for example, a tube/cartridge, containing a selected oil or other source of fragrance into the air line of the nasal cannula or mask that is coupled, in use, to the dispenser outlet.
In an alternative embodiment, the apparatus may be adapted to introduce fragrance into the airline upstream of the dispenser outlet within the housing. To this end, one or more fragrance holding vessels may be coupled to the pipework leading to the dispenser outlet from the oxygen concentrator and where there are several such vessels with different fragrances there is suitably a means of switching between them. This arrangement may be particularly suitable where the apparatus is to be used in a domestic or other environment where the facility for rapid change over between a wide range of different fragrances is not of such great importance.
Turning to a second aspect of the present invention there is provided an oxygen dispenser for dispensing substantially pure oxygen or highly oxygen-enriched air, which dispenser comprises a housing accommodating an oxygen concentrator in fluid communication with an air inlet of the housing and a dispenser outlet of the housing via pipework, a flow control valve to control flow of oxygen or oxygen-enriched air to the dispenser outlet, the flow control being under the control of a controller and wherein the valve is a solenoid-operated valve which is operated by the controller to dispense a volume of oxygen or oxygen enriched air in response to activation of a switch means. The switch means may be a manually operated electrical switch or may be an electrical switch that is automatically activated by coupling a dispensing cannular or dispensing mask or the like to the dispenser outlet and suitably deactivated by uncoupling of the dispensing cannular mask or the like from the outlet.
The volume of oxygen dispensed is suitably a predetermined volume and may be controlled by dispensing at a known rate (which may be fixed at the outset or variable but monitored) for a controlled period of time. The controller accordingly preferably has a timer for timing the duration of a dispensing session.
Preferably the oxygen dispenser of the invention further comprises one or more flow sensors to sense the rate of dispensing flow of oxygen or oxygen enriched air and being operatively linked to the controller.
Preferably the oxygen dispenser of the invention further comprises one or more oxygen level sensors to sense the level of oxygen or oxygen enriched air being dispensed by the dispenser and/or the level of oxygen in the air being drawn into the oxygen concentrator, the oxygen level sensor(s) being operatively linked to the controller.
Suitably each oxygen level sensor forms part of a negative feedback loop with the controller. The signals from the oxygen level sensor(s) may be processed by the controller to dictate opening and or closure of the control valve to facilitate achievement and/or maintenance of a desired level of oxygen.